Mother: No! I tell you no! I won't have you bringing some young girl in for supper! By candlelight, I suppose, in the cheap, erotic fashion of young men with cheap, erotic minds! Norman Bates: Mother, please...!

When Janet Leigh is shown lying dead on the floor of the shower, there is a close-up of her open eye. The pupil is contracted to a pinpoint (obviously due to the bright lighting) where it should have been dilated. After the film was released, Hitchcock heard from several ophthalmologists who pointed this out and suggested he use belladonna eyedrops in the eyes of "dead" people in future films, as the chemical prevents the pupils from contracting.